Nearly 40% of US Electricity Could Come From Rooftop Solar

The National Renewable Energy Laboratory has found that nearly 40 percent of electricity in the U.S. could come from rooftop solar photovoltaics, according to a new study . The total figure, 1,118 gigawatts, is nearly double the previous estimate of 664 gigawatts that NREL calculated in 2008. The increase is due mostly to increasing module power density, more granular data and a better grasp of building suitability for solar. "This report is the culmination of a three-year research effort and represents a significant advancement in our understanding of the potential for rooftop PV to contribute to meeting U.S. electricity demand," Robert Margolis, NREL senior energy analyst and co-author of the report, said in a statement. NREL brought together ZIP-code-level data with rooftop suitability characteristics, including light detection and ranging (lidar) data and technical gen...